【摘 要】
：
As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,long-time rapid movement and chemical reaction.Exis
【机 构】
：
School of Chemical Engineering,Northwest University,Xi’an 710069,China;Research Institute of Shaanxi
论文部分内容阅读
As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,long-time rapid movement and chemical reaction.Existing evaluation methods for attrition resistance,such as ASTM D5757 and Jet Cup test,are targeted for fresh catalysts at ambient temperature,which cannot well reflect the real process.In this study,spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing,in which the catalyst attrition under differ-ent system temperatures,running time and process factors was investigated with percent mass loss (PML),particle size-mass distribution (PSMD) and scanning electron microscope (SEM).Carbon deposition on the catalyst before and after activation,aromatization and regeneration was analyzed by thermogravimetry(TG),and the attrited catalysts were evaluated for methane dehydro-aromatization (MDA).The results show that the surface abrasion and body breakage of catalyst particles occur continuously,with the increase of system temperature and running time,and make the PML rise gradually.The process factors of activation,aromatization and regeneration can cause the catalyst attrition and carbon deposits,which broaden the PSMD in varying degrees,and the carbon-substances on catalysts greatly improve their attrition resistance at high temperature.Catalyst attrition has a certain influence on its catalytic performance,and the main reasons point to particle breakage and fine powder escape.
其他文献
Hydrophilic modification is a promising method to inhibit fouling formation on ultrafiltration membrane.In this work,different mass concentrations (1％-16％) of hydrophilic polyvinylpyrrolidone were incorpo-rated into polyethersulfone (PES) membranes fabric
Study on gas-liquid flow in stirred tank with two combinations of dual-impeller (six-bent-bladed turbine(6BT)+six-inclined-blade down-pumping turbine (6ITD),the six-bent-bladed turbine (6BT)+six-inclined-blade up-pumping turbine (6ITU)) was conducted usin
A series of iron (Fe) modified CuO-ZnO-ZrO2-Al2O3 (CZZA) catalysts,with various Fe loadings,were pre-pared using a co-precipitation method.A bifunctional catalyst,consisting of Fe-modified CZZA and HZSM-5,was studied for dimethyl ether (DME) synthesis via
Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been derive.To make the model more applicable,the effects of time and the conversion degree on the reaction rate parameters were considered.Two type
The hydrogenation of levulinic acid (LA) to y-valerolactone (GVL) by using water as solvent is a crucial process in the production of fine chemicals from biomass.An ultrathin carbon layer coating CoRu bimetallic catalyst supported on silica (CoRu@C/SiO2)
Chemical looping reforming (CLR) is a recent trend for syngas production,which has several merits compared to the conventional manner.One of the most important issues for CLR is to find low-cost mate-rial as oxygen carriers,so iron is a promising candidat
Chemical looping gasification (CLG) is a promising technology for high-quality syngas production.One key issue to successful CLG is the selection of high-performance oxygen carrier.In this study,several Ca-and Mg-rich steelmaking wastes from steel industr
Isooctane attracts great interest in recent years because of its promising potential as friendly-environmental gasoline,which is obtained by dimerization of isobutene with a hydrogenation step.Herein,a solid acid catalyst sulfated zirconia modified by ZnO
The porous CeO2 flowerlike micro-nano spheres based materials were prepared to remove HCN effec-tively at lower temperature range.The CeO2 and a serious of porous flowerlike ceria based materials loaded with metal species including Cu,Ag,Ni,Co and Fe were
An electrolyte Equation of State is presented by combining the Cubic Plus Association Equation of State,Mean Spherical Approximation and the Born equation.This new model uses experimental relative static permittivity,intend to predict well the activity co